In industries with manufacturing processes involving fluids, numerous pumps and other rotary shaft devices are required for the transport and handling of fluids such as slurries and chemical solutions. The flushing water requirements of these seals for seal lubrication and radial emission suppression greatly increased operational water requirements and increased the volumes of liquid wastes requiring treatment to remove environmental pollutants.
Our dry-face rotary seals were developed to solve these problems. These seals rely on unlubricated dry contact between a resilient seal member and a hard smooth surface of an opposed sealing member, the pressure at the contact surface between these two members being sufficient to prevent passage of liquid therebetween. The normally high friction between such elastomeric materials and hard surfaces would appear to so severely limit the useful life of such seals that they would not be practical. One would expect that liquid lubricants would be required to reduce this friction.
However, we have found that if the contact area of the resilient member is minimized, the resilient materials at the contact area are stress hardened, the polymeric components aligned in a direction parallel to the hard sealing surface, and heat transfer elements are provide to remove heat from the sealing contact surfaces, the life of such seals are greatly extended and satisfy industrial requirements, without liquid lubrication. Since these dry-face seals do not require flushing water either for lubrication or for radical emission suppression, they are revolutionizing the field of rotary seals.